Many participant-sport activities are played on a hard, non-cushioned playing surface. For instance, many running tracks are asphalt, tennis courts are typically cement or composition material, and many playgrounds are cement or asphalt. These materials, e.g., asphalt, cement, wood, etc., have the distinct advantages of durability, ease of maintenance, and tolerance of temperature extremes. However, unlike a softer, cushioned, surface as grass or mats, the hard, non-cushioned surfaces are a frequent cause of injuries, especially to children in the playground environment.
Many of the composition surfaces, such as rubberized asphalt, which are somewhat elastic and more cushioned than asphalt or cement, and hence more desirable in such circumstances, are unfortunately both expensive and difficult to apply and to maintain. For these reasons, sports surfaces which are subject to a considerable amount of hard use have typically been extremely hard and non-cushioned. Such surfaces are typically easier to maintain and are capable of withstanding heavy use. In particular sports or play environments, such as school playgrounds, the likelihood of injurious contact between the user and the playing surface is relatively high, and hence such environments have typically not been made available for use unless a softer cushioned surface, such as grass, sand or sawdust, is available. In other sports, however, such as tennis, track, the risk of injury due to a hard playing surface is not as great, although still present. In many of these applications, however, where the risk of injury is not undesirably high, a cushioned playing surface may be desirable for other reasons, namely to aid in the playing of the game, but is still not used, because the cushioned surface is not sufficiently durable or adaptable to outdoor environments or is too expensive. Thus, the lack of a durable, inexpensive cushioned surface suitable for use in sports or playgrounds has had a detrimental effect on both the level and quality of those activities.
There are additional uses of cushioned protective surfaces other than for sports or playgrounds. In areas of high traffic, hard floors can cause various ailments such as bad knees and the like. On factory floors and other areas in which people must stand, hard floors can cause back and other problems. In physical therapy facilities, the use of hard floors is also minimized to prevent injury. Protective surfaces are particularly needed in those environments which are susceptible to extreme temperature change or other environmental hazards.
Rubber flooring is one alternative used to minimize impact. The rubber flooring can be used in all of the environments described above. These floors generally consist of a top layer or wear surface and a backing layer that provides the cushioning and shock absorption characteristics required for the particular application.
One such protective flooring is described in U.S. Pat. No. 6,623,840. The protective flooring tile disclosed has a durable and water resistant prefabricated top layer which is made of rubber material. The top layer has a top surface and a bottom surface, with the bottom surface having voids which extend from bottom surface toward the top surface. A resilient bottom layer extends from the top surface and is made of granulated rubber. The bottom layer has a prepolymer material provided between the granulated rubber which bonds the granulated rubber together. The prepolymer material flows from the bottom layer into the voids of the top layer during the manufacture of the protective flooring tile to bond the top layer to the bottom layer. The density of the top layer of the protective flooring tile is greater than the density of the bottom layer, which allows the top layer to provide the water resistant characteristics required for harsh environments. The prefabricated top layer may also have controlled geometric patterns provided therein.
While rubber floorings can be effective for providing cushioning and protecting against injury from impact, current products offered in the market have various limitations. The rubber floors which are made from one material generally have porous surfaces which allow the penetration of the liquid into the tile, resulting in damage to the tile. Flooring made from different materials have different densities associated with the materials, which can cause problems with dimensional instability and with curling and lifting of the corners. Therefore, it would be beneficial to provide a cushioned flooring which could be used in sports facilities, restaurants, factories, and playgrounds which has the dimensional stability to be used in all environments both indoors and outdoors.